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1
Orlov, G. A., V. V. Kotov und A. G. Orlov. „ANALYSIS OF THE WALL THICKNESS VARIATION OF PIPES UNDER INTERNAL PRESSURE“. Izvestiya Visshikh Uchebnykh Zavedenii. Chernaya Metallurgiya = Izvestiya. Ferrous Metallurgy 61, Nr. 6 (28.07.2018): 494–95. http://dx.doi.org/10.17073/0368-0797-2018-6-494-495.
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A computer simulation of the internal pressure expanding was performed for pipes with uneven wall thickness made of steel, aluminum and titanium alloys. For this simulation software tool ESI Virtual-Performance 2016.0 was used that implements the finite element method. The convergence and accuracy of the solution was estimated by comparison with known solutions. A full factorial computational experiment was performed by varying factors: the initial wall thickness variation of pipes, D/S and parameter of alloys hardening. The regression equations were obtained by the internal pressure at the time of destruction and final wall thickness variation from these factors. It was found that the variation in wall thickness in the distribution pipe rupture occurs in the thin wall. A wall with minimum thickness continues thinning with an almost constant maximum wall thickness, which leads to an increase in the transverse variation in wall thickness. It was concluded that the increase of the initial variation in wall thickness pipe speeds up the process of rupture in the area of thin wall. It is recommended in conduits conducting high-pressure fluid to apply pipes with minimal variation in wall thickness.
2
Liu, Heng, Yu Qing Xiong und Ji Zhou Wang. „Kinetics Study of Aluminum Deposition on Inner Wall of Pipes by Atomic Layer Deposition“. Advanced Materials Research 482-484 (Februar 2012): 627–32. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.627.
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In this paper, feasibility of aluminium deposition on inner wall of pipes by atomic layer deposition was studied. Firstly, by solving kinetics equation of gas adsorption on the pipe inner wall, the time for the reactant to reach saturated adsorption on the wall was calculated. Secondly, according to the aluminium crystal structure, the thickness of each deposition cycle was obtained. Finally, the minimum aluminium thickness and number of atomic layer deposition cycles that can meet electromagnetic requirement of wave guide was calculated.
3
Zirakashvili, Natela. „Applied Systems Theory: Mathematical and Numerical Simulation of Strength of Thick-wall Pipe by Using Static Elastic Problems“. International Journal of Circuits, Systems and Signal Processing 15 (06.09.2021): 1346–64. http://dx.doi.org/10.46300/9106.2021.15.145.
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In Systems Theory, the Mathematical and numerical simulation of strength of thick-wall pipe by using static elastic problems is an important problem and has attracted the attention of many researches, academicians and practitioners. the The present work studies the change in the strength of a quite long isotropic thick-wall pipe (circular cylinder) for the varying pipe diameter, wall thickness and material. The pipe is in the plane deformed state, i.e. plane deformation is considered. Based on the problems of statics of the theory of elasticity, a mathematical model to calculate the strength of the thick-wall pipe was developed and the problems of statics of the theory of elasticity were set and solved analytically in the polar coordinate system. The analytical solution was obtained by the method of separation of variables, which is presented by two harmonious functions. The dependence of the pipe strength on the thickness and material of the pipe wall, when (a) normal stress is applied to the internal boundary (internal pressure) and external boundary is free from stresses and (b) normal stress is applied to the external boundary (external pressure) and the internal boundary is free from stresses, is studied. In particular, the minimum thicknesses of the walls of homogeneous isotropic circular cylinders of different materials and diameters with a plane deformed mode when the pressures in the cylinders do not exceed the admissible values were identified. Some numerical results are presented as tables, graphs and relevant consideration.
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Štafura, Andrej, Katarína Tuhárska, Štefan Nagy und Anna Danihelová. „INFLUENCE OF THE THICKNESS OF THE BACK WALL OF A WOODEN ORGAN PIPE AND THE AIR PRESSURE IN THE WIND CHEST ON ITS SOUND PROPERTIES“. Akustika, VOLUME 37 (15.12.2020): 86–93. http://dx.doi.org/10.36336/akustika20203786.
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The paper presents the results of the study of the influence of the back wall thickness of an organ pipe made of resonant spruce wood and the air pressure in the wind chest on its frequency spectrum. A wooden organ pipe with a replaceable back wall was used in the experiment. The wooden plate used for the back wall had an initial thickness of 7 mm. The plate was gradually thinned in 1 mm decrements to a thickness of 1 mm. For each plate thickness, the frequency spectrum was scanned at four different air pressures, namely 588 Pa, 716 Pa, 814 Pa and 941 Pa. The results of the experiment showed that at a given back wall thickness, the fundamental tone frequency increases with increasing air pressure. The decrease in the back wall thickness was manifested by a decrease in the fundamental frequency. At an air pressure of 716 Pa, the intensity of the fundamental as well as the second harmonic component of the pipe acoustic spectrum increased slightly at all wall thicknesses. With increasing air pressure, the intensity of higher harmonic frequencies also increased. The decrease in the back wall thickness of the wooden organ pipe had only a minimal effect on the intensity of the individual harmonic components of the frequency spectrum. Changing the thickness of the back wall of a wooden organ pipe will not significantly affect its final sound.
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Zhao, Shixiang, und Yulia Pronina. „On the stress state of a pressurised pipe with an initial thickness variation, subjected to non-homogeneous internal corrosion“. E3S Web of Conferences 121 (2019): 01013. http://dx.doi.org/10.1051/e3sconf/201912101013.
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The paper concerns 2D problem of an elastic thick-walled pipe with an initial thickness variation, subjected to internal pressure and mechanochemical corrosion. The inner perimeter of the pipe cross-section is elliptical, while the outer is circular. The linear Dolinskii corrosion kinetics model is used. In the general case, structural instability of initial boundary value problems with unknown evolving boundaries can cause the divergence of numerical procedures when modelling the processes under study. It is observed that the attempts to circumvent the divergence of numerical procedure can suppress the manifestation of mechanochemical effect and yield inaccurate results. Thus, it is necessary to find a compromise between competing computational processes. Calculations revealed that the variation of the initial pipe wall thickness within the acceptable pipe wall tolerance can noticeably accelerate the growth of stresses and, consequently, reduce the durability of the pipe. The applicability of analytical solutions for a perfect circular pipe with a reduced thickness, equal to the minimum thickness of the imperfect pipe, to the case under study is also discussed.
6
Kosmatskii, Ya I., K. Yu Yakovleva, N. V. Fokin, V. D. Nikolenko und B. V. Barichko. „Application of physical simulation at study of pipe production processes“. Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 77, Nr. 3 (28.03.2021): 320–26. http://dx.doi.org/10.32339/0135-5910-2021-3-320-326.
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Physical experiments allow to obtain maximum information on a studied process at minimal cost, ensuring its higher accuracy comparing with data, obtained by mathematical simulation and avoiding risks, which can occur at industrial testing of new technological modes. Results of studies of deformation in the process of pipes production by extrusion presented. The studies were accomplished at laboratory test units, developed by specialists of the laboratory of drawing and extrusion of JSC “RusNITI”. One of the basic problems at pipes production by extrusion is ensuring minimal possible wall non-uniform thickness. It was noted that the relation between plunger die moving speeds during sleeve pressing-out and immediate pipe extrusion has a significant effect on pipe wall non-uniform thickness. Computer simulation of the pipe extrusion process, accomplished by application QForm program shown that minimal values of wall non-uniform thickness corresponded to relation abovementioned speeds as 0.5–0.8. To check the data, a physical simulation of extrusion process of lead cylinder samples, having outside diameter of 18.94 mm and wall thickness 5.19–5.32 mm was accomplished. For the extrusion, a universal servohydraulic system of dynamic test Shimadzu Servopulser was used. Within the physical experiment a dependence was established between pipe wall non-uniform thickness on relation between speeds of pressing-out and extrusion. The revealed regularity was confirmed during pilot production of a pipe lot at the 55 MN force extrusion line. Another physical simulation of extrusion of 10.0×2.0 mm pipe-samples made of C1 grade lead was accomplished with one- and twothread helical ribbing of internal surface. For its accomplishment an experimental module was designed and manufactured. It was established that rotation speed of the extrusion mandrel had no significant effect on extrusion force. Metallographic studies shown that the extrusion mandrel rotation speed contributes to considerable increase of pipes surface hardness and obtaining finer grain comparing with the classic extrusion method. The technical ability of pipes production with internal helical ribbing by hot extrusion method was confirmed. The results of the study became a base for elaboration of a technology of pipes production at Volzhsky pipe plant according to ТУ 14-3Р-157–2018 “Steel seamless hot-extruded pipes with helical ribbing of internal surface for steam boilers”. Results of physical simulation of pipe drawing process at self-adjusting mandrel with application of lubricant materials of various viscosity. The data obtained were used for elaboration of a technology for production of cold-deformed pipes with internal diameter of 6.0–12.0 mm at Sinarsky pipe plant.
7
Xu, Zhi Qian, Xiang Zhen Yan und Xiu Juan Yang. „Sealing Structure Design and Analysis of Non-API Pipe Connection“. Applied Mechanics and Materials 34-35 (Oktober 2010): 811–14. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.811.
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In this paper, the main design parameters of seal structure for non-API pipe connection are studied. First, as the total contact pressure consists of the radial preload generated by interference fit and the radial pressure caused by gas pressure in pipe, the variation laws of their values changing with the sealing diameter are analyzed. The sealing diameter value which maximizes the total contact pressure can be obtained from the derivation formula for calculating the total contact pressure. Second, considering the yield condition of pipe connection under the internal and the external pressures, the minimum wall thickness of the seal structure is derived. Then the cone angle is calculated by the sealing length and the minimum wall thickness known. Finally, take the 7in casing connection for example, the main design parameters are calculated by the above analysis.
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Zhuang, Yan, Junhao Chen, Jian Zhang, Jianlin Wang und Han Li. „Analysis of the Development Characteristics and Influencing Factors of Freezing Temperature Field in the Cross Passage“. Advances in Civil Engineering 2021 (05.03.2021): 1–11. http://dx.doi.org/10.1155/2021/6645139.
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Based on the analysis of the temperature measurement data of the Shanghai Metro Line 15 cross passage freezing project, it was found that the gray silt layer of cross passage No. 2 outperforms that of cross passage No. 1 on the freezing effect, which is mainly attributed to the large loss of cooling capacity in the latter passage. Within the same stratum, the soil temperature at the duct piece is higher than that of the deep soil. When the soil freezes for 45 days, the temperatures of the sandy silt and gray silt layers of the same cross passage drop to −8.25°C and −6.91°C, respectively, indicating that the freezing effect of the sandy silt layer is better than that of the gray silt layer. Moreover, simulations were performed for deviation freezing pipes, nondeviation freezing pipes, and different freezing pipe diameters in the cross passage No. 1, respectively. It was found that the maximum difference of the closure completion time between the deviation and nondeviation freezing pipes is 6 days. Furthermore, for deviation freezing pipes and nondeviation freezing pipes at the center of the cross passage, the minimum difference in the freezing wall thickness reduces from 0.45 mm after 20 days of freezing to 0.06 mm after 45 days of freezing, indicating that the difference in the freezing wall thickness gradually weakens as freezing develops gradually. The deviation freezing pipe increases the spacing of freezing pipes in the deep soil. As the pipe spacing increases, the influence of the pipe diameter on the closure completion time of the freezing wall decreases.
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Rahmansyah, Abdul, Zulfikar Zulfikar und Bobby Umroh. „Manufacture of Water Pipe From Clampshell Powder Materials“. JOURNAL OF MECHANICAL ENGINEERING, MANUFACTURES, MATERIALS AND ENERGY 2, Nr. 2 (28.12.2018): 73. http://dx.doi.org/10.31289/jmemme.v2i2.2105.
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<h1>In general, household waste water pipelines use plastic pipes of PVC type that are not environmentally friendly and are relatively expensive. Therefore, this research will design molds and manufacture of composite pipes using raw materials of clampshell powder. The raw material used is clampshell powder with the composition of MgO and CaO compounds which is about 22.28% and 66.70%. The mixture of materials used consisted of clampshell powder with a size of 40 mesh, catalyst, and unsaturated polyester resin as a matrix. The objective of this study is manufacture of water pipes made from polymer composites reinforced by clampshell powder. Composite pipe manufacturing is carried out using the casting method. Pipe molds are made of stainless steel with a diameter of 40.46 mm (1.6 in) and an outer diameter of 50.8 mm (2 in). This mold size follows SNI 06-0084-2002 standards. The results of the study, water pipes from polymer composite material reinforced by clampshell powder with an inner diameter size of 40.64 mm and varying outside diameter. This variation depends on the composition of the clampshell powder in composite materials. The greater the clampshell powder composition, the more easily the maximum pipe wall thickness can be obtained. The average wall thickness variation is 3.35 mm. This variation is still included in the polymer water pipe requirements, which is a minimum of 2 mm.</h1>
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Rofooei, Fayaz Rahimzadeh, Himan Hojat Jalali, Nader Khajeh Ahmad Attari, Hadi Kenarangi und Masoud Samadian. „Parametric study of buried steel and high density polyethylene gas pipelines due to oblique-reverse faulting“. Canadian Journal of Civil Engineering 42, Nr. 3 (März 2015): 178–89. http://dx.doi.org/10.1139/cjce-2014-0047.
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A numerical study is carried out on buried steel and high density polyethylene (HDPE) pipelines subjected to oblique-reverse faulting. The components of the oblique-reverse offset along the horizontal and normal directions in the fault plane are determined using well-known empirical equations. The numerical model is validated using the experimental results and detailed finite element model of a 114.3 mm (4″) steel gas pipe subjected to a reverse fault offset up to 0.6 m along the faulting direction. Different parameters such as the pipe material, the burial depth to the pipe diameter ratio (H/D), the pipe diameter to wall thickness ratio (D/t), and the fault–pipe crossing angle are considered and their effects on the response parameters are discussed. The maximum and minimum compressive strains are observed at crossing angles of 30° and 90°, respectively. It is found that the dimensionless parameters alone are not sufficient for comparison purposes. Comparing steel and HDPE pipes, it is observed that HDPE pipes show larger compressive strains due to their lower strength and stiffness. For both steel and HDPE pipes, peak strains increase with increasing D/t and H/D ratio for a constant pipe diameter and fault offset. For a given H/D ratio, compressive strains increase with increasing D/t ratio in HDPE pipes, while in steel pipes considered in this study, this effect is negligible. Finally, the peak strains of the pipes are compared to those suggested by Canadian Standard Association for Oil and Gas Pipeline System, CSA Z662.
11
Sun, Jian, und Wei Qiang Liu. „Effect of Heat Leading of Windward Leading Edge Using Heat Pipe with Porous“. Advanced Materials Research 217-218 (März 2011): 674–79. http://dx.doi.org/10.4028/www.scientific.net/amr.217-218.674.
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By the uses of finite element method and finite volume method, we calculated the solid domain and fluid domain of windward leading edge which is flying under one condition. And the paper proved that heat pipes which covered on the leading edge have effect on thermal protection. The maximum temperature of the head decreased 12.2%. And the minimum temperature of after-body increased 8.85%. Achieving the transfer of heat from head to after-body, the front head of the thermal load was weakened and the ability of leading edge thermal protection was strengthen. The effect of the thickness of heat pipe, black level of covering materials and equivalent thermal conductivity of heat pipes on the wall temperature were discussed for the selection of thermal protection materials of windward leading edge to provide a frame of reference.
12
Shang, Peng, Yun Xia Qu und Jing Jing Zhao. „Parameters Optimization of Steel Wire Reinforced Thermoplastics Composite Pipe“. Advanced Materials Research 690-693 (Mai 2013): 399–403. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.399.
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Recently the steel wire reinforced thermoplastics composite pipelines are increasingly used in many different fields. In this paper, a parametric finite element model (FEM) of Steel Wire Reinforced Thermoplastics Composite Pipe (SRTP) was established by using ANSYS parametric design language (APDL). The purpose of optimization was to reduce the cost, so the minimum of pipelines total weight was chosen as the optimization objective. The wall thickness of SRTP and the diameter and axial pitch of braided steel wire were chosen as the main optimize parameters. The whole optimization process must ensure that the bearing capacity of SRTP was not weakened, so the yield strength was chosen as the optimization constraints. The optimization results were reasonable and correct.
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DAS, DEBOPAM, und JAYWANT H. ARAKERI. „Transition of unsteady velocity profiles with reverse flow“. Journal of Fluid Mechanics 374 (10.11.1998): 251–83. http://dx.doi.org/10.1017/s0022112098002572.
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This paper deals with the stability and transition to turbulence of wall-bounded unsteady velocity profiles with reverse flow. Such flows occur, for example, during unsteady boundary layer separation and in oscillating pipe flow. The main focus is on results from experiments in time-developing flow in a long pipe, which is decelerated rapidly. The flow is generated by the controlled motion of a piston. We obtain analytical solutions for laminar flow in the pipe and in a two-dimensional channel for arbitrary piston motions. By changing the piston speed and the length of piston travel we cover a range of values of Reynolds number and boundary layer thickness. The velocity profiles during the decay of the flow are unsteady with reverse flow near the wall, and are highly unstable due to their inflectional nature. In the pipe, we observe from flow visualization that the flow becomes unstable with the formation of what appears to be a helical vortex. The wavelength of the instability ≃3δ where δ is the average boundary layer thickness, the average being taken over the time the flow is unstable. The time of formation of the vortices scales with the average convective time scale and is ≃39/(Δū/δ), where Δu=(umax−umin) and umax, umin and δ are the maximum velocity, minimum velocity and boundary layer thickness respectively at each instant of time. The time to transition to turbulence is ≃33/(Δū/δ). Quasi-steady linear stability analysis of the velocity profiles brings out two important results. First that the stability characteristics of velocity profiles with reverse flow near the wall collapse when scaled with the above variables. Second that the wavenumber corresponding to maximum growth does not change much during the instability even though the velocity profile does change substantially. Using the results from the experiments and the stability analysis, we are able to explain many aspects of transition in oscillating pipe flow. We postulate that unsteady boundary layer separation at high Reynolds numbers is probably related to instability of the reverse flow region.
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Cawley, P., M. J. S. Lowe, F. Simonetti, C. Chevalier und A. G. Roosenbrand. „The variation of the reflection coefficient of extensional guided waves in pipes from defects as a function of defect depth, axial extent, circumferential extent and frequency“. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 216, Nr. 11 (01.11.2002): 1131–43. http://dx.doi.org/10.1243/095440602761609498.
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The reflection coefficients of extensional guided modes from notches of different axial, circumferential and through-thickness extent in pipes of different diameters have been studied using finite element analysis. A selection of the predictions has also been validated by experiments. For part-thickness notches of a given circumferential extent and minimal axial extent, the reflection coefficient increases monotonically with depth at all frequencies, and increases with frequency at a given depth. When the wavelength is long compared to the pipe wall thickness, the reflection coefficient from part-thickness notches of a given circumferential extent is a strong function of the defect axial extent, the reflection being a maximum at an axial extent of about 25 per cent of the wavelength and a minimum at 0 and 50 per cent. The reflection coefficient is a linear function of the defect circumferential extent at higher frequencies (with frequency-diameter products greater than about 3000 kHz mm) where a ray theory analysis explains the behaviour, while at low frequencies the reflection coefficient at a given circumferential extent is reduced. In the high-frequency regime, the axial extent of a through-thickness defect has little influence on the reflection coefficient, while it is important at lower frequencies. Three-dimensional, finite element predictions in the high-frequency regime have shown that the reflection coefficient from a part-thickness, part-circumferential defect can be predicted by multiplying the reflection coefficient for an axisymmetric defect of the same depth and axial extent by that for a through-thickness defect of the same circumferential extent.
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Poulikakos, D., und M. Kazmierczak. „Forced Convection in a Duct Partially Filled With a Porous Material“. Journal of Heat Transfer 109, Nr. 3 (01.08.1987): 653–62. http://dx.doi.org/10.1115/1.3248138.
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This paper presents a theoretical study of fully developed forced convection in a channel partially filled with a porous matrix. The matrix is attached at the channel wall and extends inward, toward the centerline. Two channel configurations are investigated, namely, parallel plates and circular pipe. For each channel configuration, both the case of constant wall heat flux and constant wall temperature were studied. The main novel feature of this study is that it takes into account the flow inside the porous region and determines the effect of this flow on the heat exchange between the wall and the fluid in the channel. The Brinkman flow model which has been proven appropriate for flows in sparsely packed porous media and for flows near solid boundaries was used to model the flow inside the porous region. Important results of engineering interest were obtained and are reported in this paper. These results thoroughly document the dependence of the Nusselt number on several parameters of the problem. Of particular importance is the finding that the dependence of Nu on the thickness of the porous layer is not monotonic. A critical thickness exists at which the value of Nu reaches a minimum.
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Tian, Ya Qin, Zhi Fei Wang, Qing Xue Huang und Jin Bao Li. „The Study of Fulcrum Distance in the Pressure Straightening Process“. Advanced Materials Research 145 (Oktober 2010): 399–403. http://dx.doi.org/10.4028/www.scientific.net/amr.145.399.
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In order to study the impact of fulcrum distance on the straightening the minimum fulcrum distance was determined based on the plastic theory according to straightening pressure force in the process of straightening process where there was no indentation. The optimal distance between the fulcrums straightening has been studied by using of bending curvature changes in the bending deflection formula and support the relationship between the dot pitch. Given initial deflection according to bending deflection and bending deflection the amount range of the fulcrum distance can be determined during the pressure straightening. When the rate of bending deflection determined it can obtain the fulcrum distance at the same curvature. The more fulcrums distance the more bending deflection. The minimum fulcrum distance was three times the power growth with the diameter of work piece. The minimum fulcrum distance is inverse proportion to contact area of pressure head. With the pipe wall thickness decreases the minimum distance also reduced.
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Li, Xi Bing, Ming Jian Li, Ming Li und Ying Si Wan. „Research on Thermal Resistance of Micro Heat Pipe with Trapezium-Grooved Wick“. Key Engineering Materials 693 (Mai 2016): 395–402. http://dx.doi.org/10.4028/www.scientific.net/kem.693.395.
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As an efficient heat conducting unit, micro heat pipe is widely used in high heat flux microelectronic chips, and thermal resistance is one of the factors that are crucial to its heat transfer capacity. Based on heat transfer theory, this paper established a theoretical model of total thermal resistance through analyzing the structure and heat transfer performance of circular heat pipe with trapezium-grooved wick, simplified the model and tested the micro heat pipe for its total thermal resistance performance by setting up a testing platform. The testing results show that when the micro heat pipe is in the optimal heat transfer state, its total thermal resistance well coincides with that from the established theoretical model. As for a micro heat pipe with trapezium-grooved wick, its total thermal resistance first decreases, then increases with heat transfer capability increment, and reaches the minimum when it is in the optimal state of heat transfer performance. That too much working fluid accumulates in evaporation section and the vapor velocity is rather low is the main cause for the greater thermal resistance when the pipe is in low heat transfer quantity, yet the greater total thermal resistance when the pipe is in high heat transfer quantity is mainly caused by the working fluid drying up in condensation section. The total thermal resistance is related to many factors, such as the thermal conductivity of tube-shell material, wall thickness, wick thickness, the number of the grooves, the lengths of condensation and evaporation sections, the diameter of vapor cavity etc.. Therefore, the structure parameters of a micro heat pipe with trapezium-grooved wick should be rationally designed according to specific conditions to ensure its heat transfer capacity and total thermal resistance to meet the requirements and be in the optimal state.
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Feder, Judy. „Sour-Service Risers and Accessories for HP/HT Application in the Gulf of Mexico“. Journal of Petroleum Technology 73, Nr. 03 (01.03.2021): 60–61. http://dx.doi.org/10.2118/0321-0060-jpt.
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This article, written by JPT Technology Editor Judy Feder, contains highlights of paper OTC 30558, “Development and Implementation of Heavy-Wall, High-Strength, Sour-Service Accessory and Risers for HP/HT Application in the Gulf of Mexico,” by Carine Landier, Jonathas Oliveira, and Christelle Gomes, Vallourec, et al., prepared for the 2020 Offshore Technology Conference, originally scheduled to be held in Houston, 4–7 May. The paper has not been peer reviewed. Copyright 2020 Offshore Technology Conference. Reproduced by permission. As oil and gas development in the Gulf of Mexico increasingly requires high-pressure/high-temperature (HP/HT) applications, the need for sour-service (SS) resistance also has grown. To meet these needs, continual innovation and improvement is needed in SS-grade materials from a technical and cost-effectiveness perspective. The complete paper discusses the material properties achieved with several large-diameter, heavy-wall SS pipes. The complete paper presents a detailed, illustrated discussion of the applications for the high-strength SS pipe and its manufacturing process. Applications The authors write that improved materials to meet HP/HT requirements such as those in the Gulf of Mexico are needed particularly for two applications: for risers, which require high-strength, thick-wall sour service; and as a substitute for corrosion-resistant alloy (CRA) with sour carbon material on defined accessories. Vallourec has developed high-strength [125,000-psi specified minimum yield strength (SMYS)] and resistant carbon steel pipes in sizes with outer diameter (OD) up to 23 in. and wall thickness up to 2.5 in. These sizes are common in lower-strength material, but meeting the high-pressure requirements with higher-grade material enables cost savings and eliminates some CRA components. It also enables the use of much-lighter-weight pipe than the 80,000-psi SMYS material that is standard for SS applications in oversize OD and heavy wall. Risers. Most deepwater drilling is performed with classic subsea blowout-preventer (BOP) systems. Access to the well through the BOP is accomplished with low-pressure, large-diameter (19-in. internal diameter) drilling riser pipe. Pipes are supplied in weldable grades (API 5L X65–X80). Large-diameter forged flanges are then welded onto the tubes. Connections are made by multiple bolts. High pressures, required as part of the drilling process, are supplied by small-diameter choke-and-kill lines. This system has served the industry well, but, as well pressures increase, so have cost and feasibility requirements of subsea BOP technology. These costs, driven by the complexity of redundant systems, have driven a desire to explore an alternative solution—a surface BOP with high-pressure drilling riser pipe. Using a surface BOP reduces the complexity and cost of the system significantly because of the ability to inspect it. The drilling riser then carries the pressure to the surface and must be able to contain it. The high-pressure environment that instigated a new solution was based on a 15,000-psi well pressure with NACE Region 2 SS performance. Because of the requirement for weldable grades for attaching the flange as well as SS, the maximum yield strength has been limited to 80,000 psi. At that strength, a very high wall thickness is required to meet 15,000 psi and greater. This becomes very heavy and can be limited by the rig hook-load capacity. Alternatives in weldable grades are nickel-based alloys with SS performance. A full string, however, is prohibitively expensive.
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Hasan, Dr Basim O. „Heat Transfer Analysis in Annular Two Phase Flow Using Finite Difference Method“. Journal of Petroleum Research and Studies 4, Nr. 1 (01.06.2013): 71–99. http://dx.doi.org/10.52716/jprs.v4i1.90.
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Heat transfer in two phase flow is widely encountered in oil and gas industry in which heat is transported between two phase the fluid and the pipe wall with a rate depending on the hydrodynamic conditions. In present work, theoretical study was carried out to predict the temperature distribution within the liquid layer in annular gas–liquid (air–water) of two phase flow in presence of heat flux under laminar flow conditions. The temperature distribution was evaluated at different values of liquid Reynolds number (ResL), gas Reynolds number (Resg), wall heat flux, and inlet liquid as well as gas temperatures. The finite differences technique was employed to solve the energy equation to obtain the temperature distribution in the liquid layer. Additionally, the effect of Resg and ResL on the liquid layer thickness was investigated and discussed. It was found that the presence of heat flux through the pipe wall leads to an increase in the liquid temperature asymptotically with the axial distance (z) depending on the radial distance (r). The maximum increase occurred in the liquid layers adjacent to the pipe surface layers and the minimum increase was at the interface. The fully developed temperature profile varied with radial distance (r) where the surface layers reached at Lt/d=5. However, the Lt/d for the layers nearest to the interface was less than 5. At a particular (r) and constant Resg, the higher the ResL is, the higher the temperature will be. At a particular ResL and Resg, the liquid layer temperature distribution depends largely on the values of applied heat flux and the gas temperature.
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Li, Xi Bing, Xun Wang, Yun Shi Ma und Zhong Liang Cao. „Research on Thermal Resistance of Micro Heat Pipe with Sintered Wick“. Key Engineering Materials 589-590 (Oktober 2013): 552–58. http://dx.doi.org/10.4028/www.scientific.net/kem.589-590.552.
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As a highly efficient heat dissipation unit, a micro heat pipe is widely used in high heat flux microelectronic chips, and its thermal resistance is crucial to heat transfer capacity. Through analyses of the structure and heat transfer performance of a circular heat pipe with sintered wick, the theoretical model of total thermal resistance was established on heat transfer theory, and then simplified, finally a testing platform was set up to test for total thermal resistance performance. The testing results show that when the micro heat pipe is in optimal heat transfer state, its total thermal resistance conform well with that from the theoretical model, and its actual thermal resistance is much lower than that of the rod made of the material with perfect thermal conductivity and of the same geometric size. With the increment of heat transfer capability, the total thermal resistance of a micro heat pipe with sintered wick decreases first, then increases and reaches the minimum when it is in the optimal heat transfer state. The greater total thermal resistance in low heat transfer performance is mainly caused by too much working fluid accumulating in evaporator and the lower velocity in vapor cavity, and the greater total thermal resistance in high heat transfer performance is mainly due to the working fluid drying up in condenser. Total thermal resistance is related to many factors, such as thermal conductivity of tube-shell material, wall thickness, wick thickness, copper powders grain size and porosity, the lengths of condenser and evaporator, and the diameter of vapor cavity etc.. Therefore, the structure parameters of a micro heat pipe with sintered wick should be reasonably designed according to the specific conditions to ensure its heat transfer capacity and total thermal resistance to meet the requirements.
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Busse, A., N. D. Sandham, G. McHale und M. I. Newton. „Change in drag, apparent slip and optimum air layer thickness for laminar flow over an idealised superhydrophobic surface“. Journal of Fluid Mechanics 727 (28.06.2013): 488–508. http://dx.doi.org/10.1017/jfm.2013.284.
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AbstractAnalytic results are derived for the apparent slip length, the change in drag and the optimum air layer thickness of laminar channel and pipe flow over an idealised superhydrophobic surface, i.e. a gas layer of constant thickness retained on a wall. For a simple Couette flow the gas layer always has a drag reducing effect, and the apparent slip length is positive, assuming that there is a favourable viscosity contrast between liquid and gas. In pressure-driven pipe and channel flow blockage limits the drag reduction caused by the lubricating effects of the gas layer; thus an optimum gas layer thickness can be derived. The values for the change in drag and the apparent slip length are strongly affected by the assumptions made for the flow in the gas phase. The standard assumptions of a constant shear rate in the gas layer or an equal pressure gradient in the gas layer and liquid layer give considerably higher values for the drag reduction and the apparent slip length than an alternative assumption of a vanishing mass flow rate in the gas layer. Similarly, a minimum viscosity contrast of four must be exceeded to achieve drag reduction under the zero mass flow rate assumption whereas the drag can be reduced for a viscosity contrast greater than unity under the conventional assumptions. Thus, traditional formulae from lubrication theory lead to an overestimation of the optimum slip length and drag reduction when applied to superhydrophobic surfaces, where the gas is trapped.
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Eisinger, F. L. „Designing Piping Systems Against Acoustically Induced Structural Fatigue“. Journal of Pressure Vessel Technology 119, Nr. 3 (01.08.1997): 379–83. http://dx.doi.org/10.1115/1.2842319.
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Piping systems adapted for handling fluids such as steam and various process and hydrocarbon gases through a pressure-reducing device at high pressure and velocity conditions can produce severe acoustic vibration and metal fatigue in the system. It has been determined that such vibrations and fatigue are minimized by relating the acoustic power level (PWL) to being a function of the ratio of downstream pipe inside diameter D2 to its thickness t2. Additionally, such vibration and fatigue can be further minimized by relating the fluid pressure drop and downstream Mach number to a function of the ratio of downstream piping inside diameter to the pipe wall thickness, as expressed by M2 Δp = f(D2/t2). Pressure-reducing piping systems designed according to these criteria exhibit minimal vibrations and metal fatigue failures and have long operating life.
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Liu, Ya Mei, Sheng Quan Liu, Liang Zhou und Liang Cun Qian. „Characteristics of Compression Wood Tracheid of Loblolly Pine Induced by Artificial Inclination“. Advanced Materials Research 528 (Juni 2012): 113–16. http://dx.doi.org/10.4028/www.scientific.net/amr.528.113.
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Three-year-old seedlings of loblolly pine (Pinus taede L.) were selected as materials in this article. The seedlings were planted in spring and divided into five groups, then were artificially inclined at the angles of 0°, 15°, 30°, 45° and 60° from the vertical. The characteristics of compression wood tracheid were observed and recorded, and their variation patterns were analyzed. The following conclusions were drawn: 1) with the increase of the inclined angle, the wall thickness of tracheid increased and the outline of the tracheid became round, the intertracheidular spaces were obvious and increased gradually in all sections derived from the inclined seedlings. The typical characteristics of compression wood were obvious when the inclined angle was bigger than 30°; 2) with the increase of the inclined angle, the tracheid length decreased firstly and then fluctuated, the minimum value reached at 30°; the tracheid width decreased firstly and then increased, the minimum value reached at 45°; the double wall thickness increased firstly and then decreased, the maximum value reached at 45°. 3) In the seedlings studied, the critical angle of inclination was about 30° or 45° from the vertical.
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Smolders, S., L. Verhoest, G. De Gueldre und B. Van De Steene. „Inspection of deteriorating asbestos cement force mains with georadar technique“. Water Science and Technology 60, Nr. 4 (01.04.2009): 995–1001. http://dx.doi.org/10.2166/wst.2009.429.
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Several breaks on asbestos cement force mains indicated a problem with these kind of force mains. An inspection technique that could give a good idea about the state of asbestos cement pipes was searched for. A georadar technique already existed to inspect drinking water mains and gravity sewers. The technique measures the wall thickness of cement containing materials and it can differentiate between ‘healthy’ and deteriorated material. The technique was applied on four wastewater force mains in Flanders. The results indicated a rapid deterioration of the asbestos cement. A deterioration mechanism called ‘calcium leaching’ was known from asbestos cement drinking water mains. Further it was known that H2S is produced in force mains and that it can attack concrete containing materials by mains of biogenic sulphuric acid attack. This research checked if both deterioration mechanisms cause the measured rapid deterioration of the asbestos cement force mains. Finally deterioration speeds and minimum required wall thickness were calculated. With the results the residual lifetimes of the force mains were calculated and these could be applied in an asset management program.
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Jones, Mark Glynne, Bin Chen, Kenneth Charles Williams, Ahmed Abu Cenna und Ying Wang. „High Speed Visualization of Pneumatic Conveying of Materials in Bypass System“. Advanced Materials Research 508 (April 2012): 6–10. http://dx.doi.org/10.4028/www.scientific.net/amr.508.6.
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Dense phase pneumatic conveying is preferable over dilute phase conveying in many industries as lower transport velocities are beneficial due to reduced attrition of the particles and reduced wear. However, dense phase conveying is critically dependent on the physical properties of the materials to be conveyed. For many materials which are either erosive or fragile, they do not exhibit the physical properties required to be conveyed reliably in a low velocity, dense phase flow regime. This can be serious problem in the food, chemical and pharmaceutical industries. One satisfactory approach which has been widely applied is the use of bypass systems. Bypass pneumatic conveying systems provide the capacity of transporting some materials that are not naturally suitable for dense phase flow. Bypass pneumatic conveying systems also provide a passive capability to reduce minimum particulate transport velocities. In this study, pneumatic conveying experiments were carried out in a 79 mm diameter main pipe with a 27 mm inner diameter bypass pipe with orifice plate flute arrangement. Alumina, fly ash and sand were conveyed in the tests. High speed camera visualization was employed to study the flow regimes of bypass pneumatic transport systems and investigate the mechanism of material blockage inhibition provided by these systems. For alumina and fly ash, it was found that particulate material blockages were inhibited in bypass systems due to the air penetration into the particulate volume as a result of orifice plate airflow resistance. For the bypass pneumatic conveying of sand, the splitting of a long plug into two smaller plugs was observed. One of the primary concerns of bypass system is the wear of the bypass line. Material such as alumina is inherently abrasive by nature. For internal bypass systems, there is limited ability to monitor the state of the inner bypass tube while in operation. The particle velocity in the pipeline has been measured from the high speed video of the flow. The experimental result also showed that the conveying velocity of bypass system is much lower when compared conventional single bore pipelines. Based on the models developed for the assessment of service life of pneumatic conveying pipelines, the thickness loss of the bypass pipe has been estimated. It has been estimated that for a 3mm bypass tube wall thickness, a wear hole is created in approximately 2.5 years for a particle velocity of 3 m/s and 4 months for a particle velocity of 10 m/s.
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Shaik, Nagoor Basha, Srinivasa Rao Pedapati, Syed Ali Ammar Taqvi, A. R. Othman und Faizul Azly Abd Dzubir. „A Feed-Forward Back Propagation Neural Network Approach to Predict the Life Condition of Crude Oil Pipeline“. Processes 8, Nr. 6 (02.06.2020): 661. http://dx.doi.org/10.3390/pr8060661.
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Pipelines are like a lifeline that is vital to a nation’s economic sustainability; as such, pipelines need to be monitored to optimize their performance as well as reduce the product losses incurred in the transportation of petroleum chemicals. A significant number of pipes would be underground; it is of immediate concern to identify and analyse the level of corrosion and assess the quality of a pipe. Therefore, this study intends to present the development of an intelligent model that predicts the condition of crude oil pipeline cantered on specific factors such as metal loss anomalies (over length, width and depth), wall thickness, weld anomalies and pressure flow. The model is developed using Feed-Forward Back Propagation Network (FFBPN) based on historical inspection data from oil and gas fields. The model was trained using the Levenberg-Marquardt algorithm by changing the number of hidden neurons to achieve promising results in terms of maximum Coefficient of determination (R2) value and minimum Mean Squared Error (MSE). It was identified that a strong R2 value depends on the number of hidden neurons. The model developed with 16 hidden neurons accurately predicted the Estimated Repair Factor (ERF) value with an R2 value of 0.9998. The remaining useful life (RUL) of a pipeline is estimated based on the metal loss growth rate calculations. The deterioration profiles of considered factors are generated to identify the individual impact on pipeline condition. The proposed FFBPN was validated with other published models for its robustness and it was found that FFBPN performed better than the previous approaches. The deterioration curves were generated and it was found that pressure has major negative affect on pipeline condition and weld girth has a minor negative affect on pipeline condition. This study can help petroleum and natural gas industrial operators assess the life condition of existing pipelines and thus enhances their inspection and rehabilitation forecasting.
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Chernykh, I. N., K. V. Shendyapin, E. A. Geim, D. V. Ovchinnikov, I. N. Krivonogov und K. V. Bol’nykh. „Study of deformation conditions at longitudinal pipes rolling from austenite steel grades“. Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 77, Nr. 3 (28.03.2021): 312–19. http://dx.doi.org/10.32339/0135-5910-2021-3-312-319.
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Stainless steels of austenite class 08–12Х18Н10Т have a high corrosion resistance, which stipulates for their wide application in various areas of industry. Technology of pipes production of the steels is rather specific and requires observation of some conditions. It was shown that temperature of a work-piece heating before deformation is an important parameter of the technology. It was noted that for the piercing of a steel work-piece with various chrome content, there is a rational temperature interval. Nonobservation of the temperature can lead to defects formation on internal pipe surface because of earlier destruction and opening of metal cavity during piercing. The choice of the rolling-out scheme has a direct effect on the work-piece forming in cross-sections. Results of hot rolling of Ø37×2,5 tube samples, manufactured of 08–12Х18Н10Т steel and carbon steel of grade 40 presented. The rolling was done at a laboratory mill. As a result of the experiment the lower limit of ovality of rolls grooves was specified for conditions of rolling of pipes from 08–12Х18Н10Т steels by 2-roll scheme. At the rolling with ovality B/H ≤1,07, defects appeared on the internal tube surface in the form of scratches caused by the mandrel. The rational range of ovality of grooves at multi-stand rolling can be from 1.08 to 1.15. According to criterion of groove overfilling by metal for steels 08–12Х18Н10Т, requirements were formed towards the groove width of the first stand of longitudinal rolling mill. The groove width must be larger than the sleeve diameter: for 3-roll scheme – at least by 2–3%, for 2-roll scheme – at least by 7.0–7.5%. Potential advantages of 3-roll scheme comparing with 2-roll scheme for rolling of 08–12Х18Н10Т steels were established as follows: lower probability of grooves overfilling by metal of the work-piece, absence of defects (scratches caused by mandrel), on the tube internal surface at minimal ovality level of 1.07, lower level of transverse pipe wall non-uniform thickness.
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MacDonald, M., A. Ooi, R. García-Mayoral, N. Hutchins und D. Chung. „Direct numerical simulation of high aspect ratio spanwise-aligned bars“. Journal of Fluid Mechanics 843 (19.03.2018): 126–55. http://dx.doi.org/10.1017/jfm.2018.150.
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We conduct minimal-channel direct numerical simulations of turbulent flow over two-dimensional rectangular bars aligned in the spanwise direction. This roughness has often been described as $d$-type, as the roughness function $\unicode[STIX]{x0394}U^{+}$ is thought to depend only on the outer-layer length scale (pipe diameter, channel half-height or boundary layer thickness). This is in contrast to conventional engineering rough surfaces, named $k$-type, for which $\unicode[STIX]{x0394}U^{+}$ depends on the roughness height, $k$. The minimal-span rough-wall channel is used to circumvent the high cost of simulating high Reynolds number flows, enabling a range of bars with varying aspect ratios to be investigated. The present results show that increasing the trough-to-crest height, $k$, of the roughness while keeping the width between roughness bars, ${\mathcal{W}}$, fixed in viscous units, results in non-$k$-type behaviour although this does not necessarily indicate $d$-type behaviour. Instead, for deep surfaces with $k/{\mathcal{W}}\gtrsim 3$, the roughness function appears to depend only on ${\mathcal{W}}$ in viscous units. In these situations, the flow no longer has any information about how deep the roughness is and instead can only ‘see’ the width of the fluid gap between the bars.
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Adi Jatmoko, Faisal, und Eny Kusrini. „Analysis of CO2 transmission pipelines for CO2 enhanced oil recovery networks: gas field X to oil field Y“. E3S Web of Conferences 67 (2018): 04009. http://dx.doi.org/10.1051/e3sconf/20186704009.
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The aim of this study is to analyze the CO2 transmission pipeline from gas field X to oil field Y by comparing alternative routes, CO2 phases, design parameters, equipment used and economic aspects, with the objective of identifying the most efficient transmission system. The 100 MSCFD of CO2 that is normally removed from gas field X will be used and transmitted to oil field Y for enhanced oil recovery (EOR). CO2 can be transported in three phases - gas, fluid or dense vapour. Because of the corrosive properties of CO2 when in contact with water, materials with high corrosion resistance, such stainless steel or reinforced carbon, should be used. Stainless steel is commonly used for the transport of corrosive fluids such as CO2 but is expensive, while the least expensive material commonly used is reinforced fibre; however, this material has low strength at high pressure. On the other hand, while carbon steel is known for its high strength and durability it has poor resistance to corrosion. Therefore, the selection of materials for pipeline construction and the design parameters applied will be studied here to determine the best option for CO2 transmission. For comparison, two alternative routes, one with existing rights of way (the ROW route) and one all-new route, will be compared with each other. Then, CO2 phase transmission will be compared for liquid, gas and dense vapour phases, together with the design parameters applied and required equipment. Pipe diameter will be calculated along with pipe wall thickness and other requirements of parameter design for transmission of CO2. Economic analysis will then be performed for each scenario to ascertain the minimum cost while still meeting necessary technical requirements. Capital expenditure (CAPEX), operating expenditure (OPEX) and other variables will be investigated and analyzed using sensitivity testing to determine the influence of each component variation on each CO2 transmission pipeline. From the analysis applied to each scenario the optimal pipeline transmission scenarios in terms of design and cost to meet the CO2 enhanced oil-recoverynetwork needs for gas field X to oil field Y will be obtained.
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Bloom, J. M. „Technical Basis for the Extension of ASME Code Case N-494 for Assessment of Austenitic Piping“. Journal of Pressure Vessel Technology 118, Nr. 4 (01.11.1996): 513–16. http://dx.doi.org/10.1115/1.2842223.
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In 1990, the ASME Boiler and Pressure Vessel Code for Nuclear Components approved Code Case N-494 as an alternative procedure for evaluating flaws in light water reactor (LWR) ferritic piping. The approach is an alternate to Appendix H of the ASME Code and allows the user to remove some unnecessary conservatism in the existing procedure by allowing the use of pipe specific material properties. The Code case is an implementation of the methodology of the deformation plasticity failure assessment diagram (DPFAD). The key ingredient in the application of DPFAD is that the material stress-strain curve must be in the format of a simple power law hardening stress-strain curve such as the Ramberg-Osgood (R-O) model. Ferritic materials can be accurately fit by the R-O model and, therefore, it was natural to use the DPFAD methodology for the assessment of LWR ferritic piping. An extension of Code Case N-494 to austenitic piping required a modification of the existing DPFAD methodology. Such an extension was made and presented at the ASME Pressure Vessel and Piping (PVP) Conference in Minneapolis (1994). The modified DPFAD approach, coined piecewise failure assessment diagram (PWFAD), extended an approximate engineering approach proposed by Ainsworth in order to consider materials whose stress-strain behavior cannot be fit to the R-O model. The Code Case N-494 approach was revised using the PWFAD procedure in the same manner as in the development of the original N-494 approach for ferritic materials. A lower-bound stress-strain curve (with yield stress comparable to ASME Code specified minimum) was used to generate a PWFAD curve for the geometry of a part-through wall circumferential flaw in a cylinder under tension and bending. Earlier work demonstrated that a cylinder under axial tension with a 50-percent flaw depth, 90 deg in circumference, and radius to thickness of 10, produced a lower-bound FAD curve. Validation of the new proposed Code case procedure for austenitic piping was performed using actual pipe test data. Using the lower-bound PWFAD curve, pipe test results were conservatively predicted (failure stresses were predicted to be 31.5 percent lower than actual on the average). The conservative predictions were attributed to constraint effects where the toughness values used in the predictions were obtained from highly constrained compact test specimens. The resultant development of the PWFAD curve for austenitic piping led to a revision of Code Case N-494 to include a procedure for assessment of flaws in austenitic piping.
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Golański, Grzegorz, Joanna Kępa, Paweł Wieczorek und Krystian Prusik. „Characterization of Precipitation Process in T24 Steel after Long–Term Ageing“. Solid State Phenomena 186 (März 2012): 296–300. http://dx.doi.org/10.4028/www.scientific.net/ssp.186.296.
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The T24 steel belongs to a new group of bainitic steels introduced currently to the power industry. Higher requirements connected with applying higher steam parameters in power units are the reason why the low-alloy steels used so far can no longer be applied. Therefore, new T24 steel has been developed in Europe on the basis of 10CrMo9-10 (10H2M) steel, which has been used in the power industry for many years, as a result of modification in its chemical composition. This modification consisted in introducing additions and microadditions of titanium, vanadium, boron and nitrogen into the base steel. As a result of the modification the new-found T24 steel is characterized by higher mechanical properties in comparison with the base steel, which allows to use the steel for tight shields in the new supercritical power units. The material for research was low-alloy bainitic T24 steel. Samples for examination were taken from a pipe section of the following size: outside diameter 44.5mm, wall thickness 7mm. Samples were isothermally aged in the air atmosphere, at the temperature of 580°C and at times up to 12 000 hours. Changes in the microstructure were observed and recorded by means of high-resolution electron microscope, JOEL JEM 3010. Identification of the precipitates was made using carbon extraction replicas and thin foils with the SAED method. The aim of research was the analysis of precipitation processes. They are extremely important in the context of long-term service and maintaining strength parameters above the minimum level. The tests were performed on T24 steel for the as-received condition (after heat treatment) and after 12 000 hours of ageing at the temperature of 580°C. The research made it possible to determine the morphology of precipitates. It also allowed to establish the sequence of precipitation process for the examined steel.
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Zapevalov, D. N., und R. K. Vagapov. „Analysis of regulatory requirements for the assessment of carbon dioxide corrosion at gas production facilities“. Issues of Risk Analysis 18, Nr. 2 (30.04.2021): 60–71. http://dx.doi.org/10.32686/1812-5220-2021-18-2-60-71.
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Aim.In many fields, the produced gas contains corrosive CO2, which, in combination with moisture and other factors, stimulates the intensive development of corrosion processes, including local ones, which requires careful attention to the assessment of the corrosiveness of operating fluids in order to select effective anti-corrosion protection. Ensuring reliable and safe operation of equipment and pipelines prevents not only man-made risks, but also no less important environmental risks, which are especially dangerous for marine underwater facilities for Arctic coastal facilities.Methods.The analysis of normative and technical documentation in the field of assessment of corrosion risks, aggressive factors of internal corrosion and operating conditions of gas and gas condensate fields has been carried out.Results.One of the criteria for assessing the corrosion hazard is the corrosion rate of steel under operating conditions. However, the normative documents predominantly regulate the general corrosion rate, which evaluates the uniform thinning of the metal. But the rate of local corrosion is in no way taken into account, which is most relevant precisely for the conditions of carbon dioxide corrosion of steel. Another tool for identifying risks can be a corrosion allowance to the pipe wall thickness, which should be selected at the design stage and which is provided to compensate for corrosion losses during the operation of gas pipelines. It is shown that the minimum corrosion allowance (3 mm) specified in the main regulatory documents is insufficient, especially for offshore facilities.Conclusion.The experience of operating gas production facilities confirms that the rate of local corrosion can reach several mm/year. To limit this, effective anti-corrosion measures should be chosen, for example, the use of corrosion inhibitors, and a reasonable level of corrosion allowance should be provided that would take into account the corresponding level of corrosion risks at the gas production facility.
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Kotani, Yuji, Hisaki Watari und Akihiro Watanabe. „Increase Characteristics of Local Wall Thickness of a Pipe during Die Forming“. Advanced Materials Research 320 (August 2011): 456–61. http://dx.doi.org/10.4028/www.scientific.net/amr.320.456.
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In recent years global warming has become a worldwide problem. Reduction of carbon dioxide emissions is one of the most important issues also in the automobile industry. This weight reduction technology is important even if applied to electric vehicles rather than gasoline vehicles, as reduction of energy consumption is an important issue. Plastic processing of hollow pipes is an important technology for realizing weight reduction of automobile components. As an example of research into pipe forming there is the research by Ohashi et al. [1-2], who have carried out processing to enlarge pipe diameters using a lost core, which achieved suppressing reduction in wall thickness and greater pipe expansion than hydroforming. In this research, a method of increasing the wall thickness of pipe by press forming was investigated. The establishment of technology for controlling the wall thickness of pipe without buckling the pipe is an important technology for weight reduction of products. Using the finite element analysis method it was predicted that it is possible to increase the wall thickness of aluminum pipe with 2mm wall thickness by approximately 20% by hollow pipe press forming. Also, it was predicted that it is possible to increase the wall thickness by approximately 30% in places by eccentric pipe wall thickness increase. Also, the effect of the metal die which has a large effect on processing a pipe from a circular cylindrical shape to a rectangular tube shape was investigated.
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Grigorenko, V. U., und S. V. Pilipenko. „Variation in wall thickness of cold-rolled pipe“. Steel in Translation 38, Nr. 9 (September 2008): 775–76. http://dx.doi.org/10.3103/s0967091208090209.
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Kotani, Yuji, Shunsuke Kanai und Hisaki Watari. „Characteristic Features of Thickness Change of Pipe during Die Forming“. Advanced Materials Research 383-390 (November 2011): 2794–800. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.2794.
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Recently the growing demand for light weight products with high strength has been increased by the rapid development of automobile and aircraft technology. Also, reduction of carbon dioxide emissions is one of the most important issues also in the automobile industry. The weight reduction technology is important even if applied to electric vehicles rather than gasoline vehicles, as reduction of energy consumption is an important issue. Plastic processing of hollow pipes is an important technology for realizing weight reduction of automobile components. As an example of research into pipe forming there is the research by Ohashi et al. [1-2], who have carried out processing to enlarge pipe diameters using a lost core, which achieved suppressing reduction in wall thickness and greater pipe expansion than hydro forming. The authors investigated into a method of increasing the wall thickness of pipe by press forming. Using the finite element analysis method it was predicted that it is possible to increase the wall thickness of aluminum pipe with 2mm wall thickness by approximately 20% by hollow pipe press forming. Also, it was predicted that it is possible to increase the wall thickness by approximately 30% in places by eccentric pipe wall thickness increase. Also, the effect of the metal die which has a large effect on processing a pipe from a circular cylindrical shape to a rectangular tube shape was investigated.
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Scarselli, D., J. Kühnen und B. Hof. „Relaminarising pipe flow by wall movement“. Journal of Fluid Mechanics 867 (28.03.2019): 934–48. http://dx.doi.org/10.1017/jfm.2019.191.
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Following the recent observation that turbulent pipe flow can be relaminarised by a relatively simple modification of the mean velocity profile, we here carry out a quantitative experimental investigation of this phenomenon. Our study confirms that a flat velocity profile leads to a collapse of turbulence and in order to achieve the blunted profile shape, we employ a moving pipe segment that is briefly and rapidly shifted in the streamwise direction. The relaminarisation threshold and the minimum shift length and speeds are determined as a function of Reynolds number. Although turbulence is still active after the acceleration phase, the modulated profile possesses a severely decreased lift-up potential as measured by transient growth. As shown, this results in an exponential decay of fluctuations and the flow relaminarises. While this method can be easily applied at low to moderate flow speeds, the minimum streamwise length over which the acceleration needs to act increases linearly with the Reynolds number.
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Sobolenko, Oleksandr, Petro Drozhzha, Nataliia Dorosh und Lina Petrechuk. „ACCURACY WALL SICKNESS OF HOT-DEFORMED PIPES STATISTICAL ANALISIS“. Modern Problems of Metalurgy, Nr. 23 (27.03.2020): 113–20. http://dx.doi.org/10.34185/1991-7848.2020.01.11.
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Pipe-rolling units with an automatic mill are a aggregate production complex that produces hot-rolled pipes of various sizes. The technological process of seamless pipes production, has many stages: flashing the billet into a sleeve, longitudinal rolling in gauge, running in a oblique rolling mill, calibrating and reducing the diameter. Each stage significantly affects the accuracy of the geometric dimensions of the pipes. One of the main parameters characterizing the accuracy of the pipes is their transverse difference namely the size and the nature of the distribution of the pipe wall thickness in the cross section. A significant reserve for saving metal is increasing the accuracy of seamless pipes to avoid different pipe wall thickness. Different pipe wall thickness makes it difficult to get quality pipe screw-thread.The conditions of metal deformation at an injection molding machine with an automatic machine do not exclude the presence of fluctuation of the pipe wall thickness. The best characteristic of the accuracy of finished pipes will be the knowledge of quantitative indicators of the transverse difference of their end sections. The purpose of this work is to determine the variation in wall thickness of hot-rolled casing by means of mathematical statistics methods.The use of statistical data processing methods makes it possible to predict the seamless pipe difference indicator. A statistical analysis of the wall thickness indicator of the end sections showed a high ratio of wall thickness symmetry. An effective way to minimize the symmetric difference component is to optimize the deformation modes along the pipe wall. In this case, a graphical analysis of the distribution of wall thickness showed that the actual difference varies in stochastic dependence. To clarify the general form of the random periodic component of such a dependence, it is advisable to apply methods of harmonic analysis, which will allow us to develop a mathematical model for determining the accuracy of pipes.
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Kotani, Yuji, Shunsuke Kanai und Hisaki Watari. „Characteristics of Wall Thickness Increase in Pipe Reduction Process Using Planetary Rolls“. Advanced Materials Research 430-432 (Januar 2012): 1241–47. http://dx.doi.org/10.4028/www.scientific.net/amr.430-432.1241.
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In recent years, global warming has become a worldwide problem. The reduction of carbon dioxide emissions is a top priority for many companies in the manufacturing industry. In the automobile industry as well, the reduction of carbon dioxide emissions is one of the most important issues. Technology to reduce the weight of automotive parts improves the fuel economy of automobiles, and is an important technology for reducing carbon dioxide. Also, even if this weight reduction technology is applied to electric automobiles rather than gasoline automobiles, reducing energy consumption remains an important issue. Plastic processing of hollow pipes is one important technology for realizing the weight reduction of automotive parts. Ohashi et al. [1-2] present an example of research on pipe formation in which a process was carried out to enlarge a pipe diameter using a lost core, achieving the suppression of wall thickness reduction and greater pipe expansion than hydroforming. In this study, we investigated a method to increase the wall thickness of a pipe through pipe compression using planetary rolls. The establishment of a technology whereby the wall thickness of a pipe can be controlled without buckling the pipe is an important technology for the weight reduction of products. Using the finite element analysis method, we predicted that it would be possible to increase the compression of an aluminum pipe with a 3mm wall thickness by approximately 20%, and wall thickness by approximately 20% by pressing the hollow pipe with planetary rolls.
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Wang, Xin Quan, Shi Min Zhang, Juan Liao, Ying Sheng Huang und Hong Liu. „Research on Horizontal Bearing Capacity of Precast Thin-Wall Steel and Spun Concrete Composite Pile“. Applied Mechanics and Materials 590 (Juni 2014): 336–40. http://dx.doi.org/10.4028/www.scientific.net/amm.590.336.
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Precast thin-wall steel and spun concrete composite pile (TSC pile) is a new type of steel-concrete composite foundation pile whose performance is between steel pile and concrete pile. 3D numerical analysis model of TSC pile was established by FEM software in this paper. By compared with the laboratory bending test results, the model’s reliability was verified, and then the bearing capacity of TSC pile under horizontal load was calculated, moreover, influences of different cross section parameters (diameter, wall thickness, steel pipe thickness, pile’s length) on the horizontal bearing capacity of TSC pile were studied. The results show that: with the increase of pile’s outside diameter, wall thickness of steel pipe, wall thickness of concrete pipe and length of pile, the horizontal bearing capacity of TSC pile is increased. The outside diameter has a biggest impact on the horizontal bearing capacity of TSC pile, then pile’s length, steel pipe’s wall thickness, and the influences of concrete pipe’s wall thickness are the least.
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Sun, Xian Ming, und Lei Wei. „Hydrocyclone Numerical Simulation and Separation Efficiency Optimization“. Applied Mechanics and Materials 670-671 (Oktober 2014): 655–58. http://dx.doi.org/10.4028/www.scientific.net/amm.670-671.655.
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For the hydrocyclone’ separation efficiency affects by many factors, this paper combined Reynolds stress model and SIMPLEC algorithm of Fluent software with orthogonal test to simulate hydrocyclone’s operating process and analysis the flow field. Different overflow pipe wall thickness values (4mm, 8mm, 12mm), volume fraction values (1%, 5%, 10%) and inlet velocities (3m/s, 4m/s, 5m/s) was considered as the separation efficiency affective factors. Results show that the overflow pipe wall thickness has greatest influence on separation efficiency. The inlet velocity is the second and the volume fraction value is the last. The optimal combination is the overflow pipe wall thickness value 8mm, the volume fraction 5% and the inlet velocity 5m/s. The overflow pipe wall thickness value increasing can decrease the turbulent kinetic energy and increase the stability of hydrocyclone flow field.
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Аvramenko, Alexander, Anedrey Garmash, Boris Gorkunov, Sergey Lvov und Anna Tyshchenko. „Electromagnetic sensor for the control of pipe wall thickness“. Bulletin of the Military University of Technology 64, Nr. 2 (30.06.2015): 35–43. http://dx.doi.org/10.5604/12345865.1156934.
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Pittman, J. F. T., G. P. Whitham, S. Beech und D. Gwynn. „Cooling and Wall Thickness Uniformity in Plastic Pipe Manufacture“. International Polymer Processing 9, Nr. 2 (Mai 1994): 130–40. http://dx.doi.org/10.3139/217.940130.
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Sánchez-Rosas, M., J. Casillas-Navarrete, J. A. Jiménez-Bernal, V. N. Kurdyumov und A. Medina. „Experimental and numerical study of submerged jets from pipes of different wall thickness for Re<1“. Revista Mexicana de Física 66, Nr. 1 (28.12.2019): 69. http://dx.doi.org/10.31349/revmexfis.66.69.
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In this work, the experimental and numerical results from the study of the effects caused in a submerged jet flow by the change in the wall thickness of the circular tube from which said flow originates are presented. For small values of the Reynolds number Re (Re\approx0.11), four cases, regarding the ratio of pipe wall thickness to its radius, are considered: (I) pipe thickness is a fourth of the radius, (II) pipe thickness is a half the radius, (III) pipe thickness is equal to the radius and (IV) pipe thickness is three times the radius. The Particle Image Velocimetry (PIV) technique was used in order to obtain experimentally the velocity and streamlines distributions. A numerical code based on the finite difference method was developed to solve the motion governing equations and the numerical results were compared with the values obtained experimentally.
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Sun, Pan Pan, Shu Zhong Wang, Yan Hui Li und Xue Dong Li. „Numerical Analysis on Heat Transfer and Oxidation Characteristics of High-Temperature Steam Pipes in Supercritical Units“. Advanced Materials Research 908 (März 2014): 81–84. http://dx.doi.org/10.4028/www.scientific.net/amr.908.81.
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In this paper, for Super304H steel, the growth law of oxide films and the heat transfer characteristics between the pipe and the working fluid were investigated by using numerical software ANSYS, which simulated comprehensively the effects of pipe size, flow rates of steam, flue gas temperature, and steam temperature on the formation and thickness of the oxide film. A bigger pipe wall thickness, a smaller steam flow rate or a higher flue gas temperature will lead the faster growth of the oxide film thickness, the heat flux density through the wall being smaller and the wall temperature being higher. With increases in steam temperature and thickness of the oxide film, the heat flux through the wall decreases with a small amplitude, and the average temperature of tube walls increases slightly.
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Ma, Li Feng, Xiao Fei Ding, Jun Zhang, Mao Kai Tian und Li Jing Gong. „State Analysis on the Main Components of Reformer Furnace Pipe Used for a Design Cycle“. Advanced Materials Research 550-553 (Juli 2012): 3121–24. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.3121.
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Comprehensive state analysis and life evaluation of the main components of reformer furnace run over service period by EPMA, microstructure and high temperature rupture property. The results show that element distribution and microstructure of reformer pipe, riser pipe, low collecting pipe and socket is normal and the remaining life is longer. The material of furnace pipe for the HK40 are able to meet the process requirement, but the wall thickness of reformer pipe is too large, affecting the thermal efficiency and the inner diameter is small to limit the catalyst and flow. It is good proposal to production enterprises that higher level of material such as ZG50Ni35Cr25NbM is selected to reduce the wall thickness properly, expand the diameter and improve efficiency. Similarly, it can also be appropriate for the riser pipe to choose a lower grade material and reduce the wall thickness and save cost.
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Pialucha, T., B. Pavlakovic, D. Alleyne und P. Cawley. „Quantitative measurement of remnant thickness in corrosion under pipe supports“. Insight - Non-Destructive Testing and Condition Monitoring 62, Nr. 11 (01.11.2020): 642–48. http://dx.doi.org/10.1784/insi.2020.62.11.642.
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There have been many attempts to quantify the wall loss in corrosion under pipe support (CUPS) applications without lifting the pipe to gain access to the corroded area, but none have yielded satisfactory quantitative results. A new method has been developed to enable quantitative estimation of wall loss in CUPS and other applications where direct access to the affected region is not possible. It uses a combination of the non-dispersive SH0 wave and the dispersive SH1 and potentially higher-order modes propagating around the pipe, both in transmission across the defect and reflection from it. The key feature is the rapid reduction in transmission and increase in reflection when the product of the frequency and the remnant wall thickness under the defect approaches the cut-off frequency of the SH1 or higher-order modes. Initial implementation of the method gives quantitative remnant wall thickness results when the wall loss is up to 50%, with qualitative indications of severity at greater defect depths. Blind trial results on a pipe with six defects show a maximum error in the estimated remaining wall thickness of 0.5 mm. The instrument currently covers pipes in the 6-24 inch diameter range and with 6-12 mm wall thickness. This will shortly be expanded and a similar tool to scan circumferentially around the pipe, transmitting and receiving SH waves in the axial direction, is also being developed. This will enable the same defect to be tested from two directions to further increase confidence in the results.
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Lu, Yang, Lin Sheng Liu und Masaharu Ishikawa. „Quantitative Evaluation of Wall Thinning of Metal Pipes by Microwaves“. Materials Science Forum 614 (März 2009): 111–16. http://dx.doi.org/10.4028/www.scientific.net/msf.614.111.
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In this paper, a method which can inspect a metal pipe in a large scale and measure the wall thinning remotely was demonstrated. A microwave network analyzer was employed to generate microwave signals propagating in the pipe where the frequency was swept from 47.38 to 47.47 GHz. A copper pipe with inner diameter of 17 mm, 1 mm wall thickness, 900 mm length, and connected with joints having the length of 17 mm and values of thickness reductions from 3 to 80% wall thickness was measured. By building up a resonance model for the microwave signals propagating in the metal pipe, and by analyzing the resonance results of the microwave signals at the receiving port, a nondestructive method was derived to determine the degree of the wall thinning in the pipe. By comparing the experimental results with the evaluation results obtained by the theoretical analysis, it is shown that the errors of the evaluation are less than 0.5% of the pipe diameter. It indicates that high precision for remote detection and quantitative evaluation of wall thinning can be achieved by using this nondestructive method.
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Zhang, Wei, Yibing Shi, Yanjun Li und Qingwang Luo. „A Study of Quantifying Thickness of Ferromagnetic Pipes Based on Remote Field Eddy Current Testing“. Sensors 18, Nr. 9 (23.08.2018): 2769. http://dx.doi.org/10.3390/s18092769.
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Remote Field Eddy Current Testing (RFECT) has broad applications in ferromagnetic pipe testing due to the same testing sensitivity to inner and outer wall defects. However, how to quantify wall thickness in the RFECT of pipes is still a big problem. According to researchers’ studies, a linear relationship exists between the wall thickness, permeability and conductivity of a pipe and the phase of the RFECT signal. Aiming to quantify wall thickness by using this linear function, it is necessary to further study the effects of pipe permeability and conductivity on the phase of the RFECT signal. When the product value of the permeability and the conductivity of a pipe remains constant, the univariate analysis and Finite Element Analysis (FEA) are employed to analyze the variations among the phase of the RFECT signal caused by different couples of permeability and conductivity. These variations are calibrated by using a nonlinear fitting method. Moreover, Multi-Frequency Eddy Current Testing (MFECT) is applied to inverse the permeability and conductivity of a pipe to compensate for the quantification analysis of wall thickness. The methods proposed in this paper are validated by analyzing the simulation signals and can improve the practicality of RFECT of ferromagnetic pipes.
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Yusa, Noritaka, Haicheng Song, Daiki Iwata, Tetsuya Uchimoto, Toshiyuki Takagi und Makoto Moroi. „Probabilistic evaluation of EMAR signals to evaluate pipe wall thickness and its application to pipe wall thinning management“. NDT & E International 122 (September 2021): 102475. http://dx.doi.org/10.1016/j.ndteint.2021.102475.
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Zhang, Xian Yong, und Jin Feng. „Oil and Gas Pipeline Residual Strength Research Based on Reliability Analysis“. Applied Mechanics and Materials 318 (Mai 2013): 562–66. http://dx.doi.org/10.4028/www.scientific.net/amm.318.562.
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Strength of residual wall thickness reliability was studied by Monte-Carlo and finite element method, based on 40in X70 steel and 48in X80 steel which were often used in oil and gas transport pipeline. Pipe with defects in different residual wall thinkness, calculated the critical residual value of wall thickness, and analysed the defect depth and width of influence on pipe reliability. The results provide basis for pipeline safety evaluation and reasonable replacement.